1. Field of the Invention
The present invention relates to an injection molding machine and, more particularly, to a speed-up mechanism for an injection molding machine.
2. Description of the Related Art
In recent years, in order to generate more accurately injected product, the injection molding machine needs high respondence and high performance to achieve high accurately injected products and high cycle molding requirements. The prior art injection molding machine utilizes a servomotor to drive a ball screw, the ball screw and a fixed nut linearly relatively move to operate a mold clamping process. However, the relative movement between the ball screw and the fixed nut generates high abrasion, which causes the injection molding machine incapable of high respondence and high rate performance.
Therefore, it is desirable to provide an improved injection molding machine to obviate the aforementioned problems.
The object of the present invention is to provide a speed-up mechanism for an injection molding machine to improve the injecting speed. The speed-up mechanism is easy to manufacture, to assemble, and the speed-up mechanism is capable of high respondence and high performance.
To achieve the objective, the speed-up mechanism of the present invention includes: a front fixed plate having a through hole at the center; a rear fixed plate arranged parallel with the front fixed plate, and the rear fixed plate having at least one through hole; at least two guide bars parallel to each other arranged between the front fixed plate and the rear fixed plate in an equal distance; a movable plate slidably arranged on the guide bars between the front fixed plate and the rear fixed plate, and capable of moving toward and way; a rotary power source fixedly attached on one side of the movable plate for providing rotary power, the rotary power source comprising a transmission device; a fixed nut mounted on the rear fixed plate; at least one ball screw having two threads in opposite directions at two ends, the front end is engaged with the transmission device for generating a radial rotation, the rear end is engaged with the fixed nut and through the rear fixed plate to generate an axial movement for the ball screw during the rotation; and at least one movable nut engaged with the front end of the ball screw to move along the ball screw during the rotation of the ball screw, the outside of the movable nut is connected to the movable plate to drive the movable plate in the axial direction during the rotation of the ball screw.
Other objectives, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.